There is an alledged exception where the pc mobo breaks up memory areas. Something about the "memory hole" that`s require to get certain older pci cards operating properly. Enabled, the OS regards the memory available just as if the OS was 32 bit afaik. Disable it, and the OS sees it all.

Mostly involves older kit tho I think, I`ve not seen a memory hole option in a bios for quite some time.

Hi purplemonkey asking here about the RAM too i see. UKCS gave you the answer and its the same here.

I had 4Gb on 32-bit system and had difficulty getting it to read it (and sometimes boot with it when OCd). I changed to 64-bit and have had no problems. Well except that my SLi is WAY faster than my CPU can cope with (8800GTXs and Q6600).

rrjwilson thanks for the info i felt it appropria to start a new topic as I have many question associated with 32bit vs 64bit debate.

Does ram on you Graphics card count towards Vista 32bits 3.2gb allowance? I.e. If i had two 512mb cards does this reduce the total ram available to windows 2.1gb given that the graphics card offers 1.1gb ram?

antivirus software is affected by 64bit vista i.e. my subscription to zonealarm would be useless as zonealarm do not support 64bit vista... what other problems might I encounter similar to these with software?

I'm struggling to see a huge benefit running Vista 64bit when it causes issues like this...

If i were running photoshop in Vista 64Bit it will run in compatibility mode under 32bit rules allowing it's 3.2gb of ram to be used... (Correct???) So if I were then to open say Adobe Illustrator it will also run in compatibility mode is this where the advantage of 64bit windows lies as it will also allow illustrator to use the 3.2gb allowance programs in compatibility mode are restrained to?

Under Vista 32bit am I correct in thinking that 3.2gb of ram would be shared between Photoshop and Illustrator???

Does ram on you Graphics card count towards Vista 32bits 3.2gb allowance? I.e. If i had two 512mb cards does this reduce the total ram available to windows 2.1gb given that the graphics card offers 1.1gb ram?

No it would not. The memory imbedded on the graphics card has nothing to do with your system memory.

Quote:

Originally Posted by name='purplemonkey'

antivirus software is affected by 64bit vista i.e. my subscription to zonealarm would be useless as zonealarm do not support 64bit vista... what other problems might I encounter similar to these with software?

There are lot's of free antivirus apps out there that support 64bit, give it a try. Since 32bit applications will be emulated on your 64bit platform, you "might" loose some performance, this is however only logical thinking and hardly what would happen irl. a 64bit OS only carry the advantage of higly optimized memory handling and support for over 4GB of memory. ie, crysis only allows 64bit OS's to create maps. Apart from that, there aren't really any difference on Vista x86 and x64.

Quote:

Originally Posted by name='purplemonkey'

If i were running photoshop in Vista 64Bit it will run in compatibility mode under 32bit rules allowing it's 3.2gb of ram to be used... (Correct???) So if I were then to open say Adobe Illustrator it will also run in compatibility mode is this where the advantage of 64bit windows lies as it will also allow illustrator to use the 3.2gb allowance programs in compatibility mode are restrained to?

Under Vista 32bit am I correct in thinking that 3.2gb of ram would be shared between Photoshop and Illustrator???

Try considering moving to a newer version of photoshop. As far as I know, CS3 supports 64bit (not quite sure). And yes, photoshop and illustrator will share the memory just as it would on a 32bit system (how could it be any different?).

No it would not. The memory imbedded on the graphics card has nothing to do with your system memory.

With a 32bit OS it does. With the drivers for the gfxcard being 32bit also, they can only access within a boundry of memory addresses. 0 to 4 gig.

If u install 4 gig in the pc, everything that pc wants to do will HAVE to take place within that 4 gig in order for the OS to be able to see it.

That includes all the devices attached to the pc, including the bigger chunk which is the gfxcard.

As an example, if u have a texture that u want to write to the gfxcard, it has to come from an address $00000000 to $ffffffff (4 gig) and write to an address $00000000 to $ffffffff. Anything outside of that boundry isn`t understood by 32bit routines.

With a 32bit OS it does. With the drivers for the gfxcard being 32bit also, they can only access within a boundry of memory addresses. 0 to 4 gig.

If u install 4 gig in the pc, everything that pc wants to do will HAVE to take place within that 4 gig in order for the OS to be able to see it.

I just checked up on it. I might have been a little too fast. Sorry my mistake. It's true, however, even if you do have 4GB installed, and are running with 1024MB on your graphics card, it shouldn't be a problem. You would just not be able to use them effectively, or to their full capacity, whatever you prefer.

I would recommend, in light of these facts, that you move on to a 64bit OS if you have 4GB or more memory installed in your system, since it would only hold your system back if you stick to 32bit. And since 64bit can handle adresses up 16.384PetaByte, you wouldn't run into that problem in our lifetime.

Driver support and compatability issues are really worrying me... last thing i want is to struggle to find drivers for all the devices etc. and having spent so long research what to put in my rig i've run out of energy to...

I think i might just stick to 32 bit...

Why bother with 64bit when 99% of programs will run in 32 bit compatibility mode and be constrained by the 3.2gig limit.

It seems to me installing anymore than 2-4gb of ram in a rig is like taking a sledgehammer to crack a nut and then using your teeth...

Driver support and compatability issues are really worrying me... last thing i want is to struggle to find drivers for all the devices etc. and having spent so long research what to put in my rig i've run out of energy to...

There's no need to worry. 64bit driver support is significantly better than a year ago. You shouldn't run into driver support issues anymore, unless you use some outdated piece of hardware.

Quote:

Originally Posted by name='purplemonkey'

Why bother with 64bit when 99% of programs will run in 32 bit compatibility mode and be constrained by the 3.2gig limit.

Again. When running in 64bit, you won't run into the memory wall, even when emulating 32bit software. The program which is emulating the 32bit software, is still using 64bit adresses. To sum it all up. Go for 64bit Vista if you have 4GB or more memory in your system. Sticking to 32bit will be the same as seeing a HD movie on an 11'' screen, just plain stupid.